Apparatus for depositing tow



April 16, 1968 H. M. COOK 3,377,675

APPARATUS FOR DEPOSITING TOW Filed Aug. 15, 1966 5 Sheets-Sheet 1 April 16, 1-968 H. M. coc

APPARATUS DEPOSITING TOW 5 Sheets-Sheet 2 7 Filed Aug. 15, 1966 7 A ril 16, 1968 Filed Aug. 15, 1966 v H. M. COOK 3,377,675

APPARATUS FOR DEPOSITING TOW 3 Sheets-Sheet 5 \c:=- I e I 4T"??? g 1 M 1 m w pr l L? I i i if IL]? United States Patent Office 3,377,675 Patented Apr. 16, 1968 3,377,675 APPARATUS FOR DEPOSITING TOW Harry Marshall Cook, Staunton, Va., assignor to E. I. du Pont de Nemours and Company, Wilmington, DeL, a corporation of Delaware Filed Aug. 15, 1966, Ser. No. 572,334 4 Claims. (CI. 28-21) This invention is concerned with means for deposition of synthetic filamentary tow and especially with apparatus and process for controlled-traverse deposition of tow in which only driven rolls contact the tow, thus minimizing mechanical damage thereto.

It is well-known to package continuous filamentary tows either between process steps or as a final product for shipment. One example of a device for directing tow into a container is illustrated in US. 2,805,765. This apparatus advances the tow between a pair of nipped belts and distributes it in a receiver by means of an oscillating spout in such a manner as to obtain a uniform lay-down. Uniform lay-down is necessary to avoid disruption of the resulting package and consequent difficulty in removal of the tow therefrom. While such apparatus as described in the above-mentioned patent is generally satisfactory for packaging of a final product, it is not completely satisfactory for packaging of some products at intermediate stages of manufacture. This is particularly true of synthetic filamentary tows which still contain appreciable quantities of spinning solvent or other swelling agents and are, therefore, especially susceptible to mechanical damage. The twin-belt type tow advancing apparatus is also difficult and expensive to maintain. A device for deposition of tow which provided efficient handling without these disadvantages would be highly desirable.

The advantages of this invention are provided in an apparatus to deposit a running length of synthetic filamentary tow into a receiver comprising a roll capable of being rotatably driven reciprocally oscillatable in a direction substantially longitudinal to the path of advance of the tow, the roll to receive the tow from a cantable guide means and to gravitationally deposit the tow in the receiver, a drive means for driving said roll, and a cantable guide means cantable through a predetermined angle to dispose the tow in a continuous lateral oscillation over a fixed length of surface of the roll.

The invention will be more readily comprehended by reference to the following description and drawings wherein: FIGURE 1 is a schematic elevation view, and FIGURE 2 is a schematic plan view of one embodiment of this invention; FIGURE 3 is a cross-section view of a preferred piddler roll; FIGURE 4 is a schematic elevation view of the drive means employed to drive the piddler and puller rolls in the embodiment shown in FIGURE 1 and FIGURE 2; FIGURE 5 is a schematic elevation view of another embodiment of the invention; FIGURE 6 is a schematic plan view of the embodiment shown in FIGURE 5.

With reference to FIGURE 1 and FIGURE 2, tow 1 (from a source not shown) is delivered by forwarding roll 2 to canting roll 3 through as long a distance as is practicable, in this embodiment, about 3 meters. Canting roll 3, driven by synchronous motor 4 through drive belt 21, is mounted on yoke 5 which is rigidly attached to shaft 6. Shaft 6 is driven by means not shown through a small angular oscillation, typically 210 to around a normal position wherein the axis of canting roll 3 is perpendicular to the normal tow path. The driving means for shaft 6 is adjustable, by means available in the art, as to both angular rate and amplitude. When canting roll 3 is maintained in its normal position, the path of the running tow will lie in a single vertical plane, as is illustrated in the figures. When it is canted through a small angle by rotation of shaft 6, the entering tow will shift to a new position on roll 3 such that its approach is again approximately to the roll axis (as is schematically illustrated by dotted lines in FIGURE 2). The resulting lateral displacement of tow from its normal path as it approaches roll 3 results in a corresponding lateral displacement on puller roll 7 and piddler roll 8. The tow drops from piddler roll 8 into receive 9, which in this embodiment is illustrated as a rectangular can. In this embodiment, rolls 7 and 8 are oscillated (by means not shown) between positions A ad B as illustrated in FIGURE 2.

A means for driving and for longitudinally oscillating rolls 7 and 8 is illustrated in FIGURE 4; as will be shown, this means also compensates for the apparent difference in tow speed as rolls 7 and 8 advance toward or recede from the tow supply, thus avoiding both slack and excessive tension in the tow between rolls 3 and 7 which would be objectionable in some high-speed operations. In some operations, the small difference is not of any real consequence and this compensation is unnecessary.

Referring to FIGURE 4 (a rear view of member 17 of FIGURE 1), timing belt 10, driven through vari-speed pulley 11 by means not shown, drives gear pulley 12 and pulley 13. Gear pulley 12 is attached to puller roll 7 through shaft 22 and pulley 13 is attached to piddler roll 8 through shaft 23. As can be observed from the positioning of pulleys 12 and 13, tow approach is from the side of plate 17 where cylinder 18 is positioned. Drive tensioner 16 maintains constant tension on belt 10. Hydraulic cylinder 18, shown in part, drives frame 19 and rolls 7 and 8 (FIGURE 1) between the limits indicated at A and B. Frame 19 is slidably mounted on stationary frame 17. The alternative extreme positions of pulley i3 and gear wheel 12 are schematically shown at 12' and 13'. Preferably, fluid is supplied to cylinder 18 in such a manner that reversals of motion of frame 19 are essentially instantaneous with immediate attainment of speed in the opposite direction. In this manner laydown of the tow is uniform over the full longitudinal traverse. In this embodiment, timing belt 10 is driven at the same speed as the tow, and the effective circumferences of driven members 12 and 13 are the same as rolls 7 and 8. Thus, as frame 19 travels from position A to position B, assuming belt 10 is traveling in a counterclockwise motion (indicated by arrow 20), the horizontal travel of driven members 12 and 13, causes a decrease in speed of rotation of the driven members.

As the frame 19 travels from position B to position A. the opposite result, occurs, i.e., an increase in the speed of rotation of driven members 12 and 13. Since the effective circumferences of driven members 12 and 13 are the same as the circumferences of rolls 7 and 8, respectively, the direction of travel of frame 19 accomplishes the rollspeed compensation necessary to correct for advance toward and retreat from the tow source by rolls 7 and 8. The change in direction of oscillation of frame 19 accomplishes exactly the roll-speed compensation needed to correct for advance toward and retreat from tow source by rolls 7 and 8 as a result of this oscillation, thus avoiding slack and excessive tension on the tow as frame 1E oscillates between positions A and B.

It is obvious that a link chain or other flexible driving member can be substituted for the belt 10. This of course would entail the use of sprockets instead of driving and driven pulleys.

Another embodiment of the invention is illustrated in FIGURE 5 and FIGURE 6. Referencing to them, tow 25 is forwarded by forwarding roll 26 to puller roll 27. The puller roll 27 feeds tow 25 to a piddler roll 28. In this embodiment, there is no canting roll, per se, but the purpose of the canting roll of the first embodiment is combined as part of the operation of the driven rolls 27 and 28. The same means for providing for longitudinal oscillation of driven rolls 27 and 28 can be used as that illustrated in FIGURE 4. This drive train will accomplish the same result in this embodiment as that heretofore described in conjunction with the embodiment of FIGURE 1 and FIGURE 2.

This version of the invention obtains lateral displacement of tow by canting the driven rolls 27 and 28. The angular displacement of the driven rolls is accomplished by rotatably mounting support frame 31, to which the driven rolls 27 and 28 are attached, on a pivot rod 30. Pivot rod is securely mounted to base member 32. Support frame 31 is oscillated through an angle measured from a line parallel to the normal path of advancing tow. Preferably, the angle of oscillation is in the range of from -1O to -';1S. When driven rolls 27 and 28 are maintained in their normal position, positions C and D of FIG- URE 6, the path of running tow will lie in a single vertical plane. When they are canted through a small angle by oscillation of support frame 31 (illustrated as position E in FIGURE 6), the entering tow will shift to a new position on the driven rolls 27 and 28 such that the running tow will again approach the roll axis at an angle of approximately 90. This lateral displacement of tow 25 on driven rolls 27 and 28 results in a corresponding lateral displacement in can 29 as the tow drops from piddler roll 28.

Oscillation of frame 31 can be accomplished by means known in the art for imparting an oscillatory motion to a linear member about a point on that member. An example is a hydraulic cylinder having its piston rod attached substantially perpendicular to support frame 31 at any given horizontal distance from pivot rod 30.

It will be obvious to one skilled in the art that it may be unnecessary to employ a puller roll (7 in FIGURE 1 and FIGURE 2; 27 in FIGURE 5 and FIGURE 6), since its employment in the herein described embodiments is to obtain the necessary tow-roller friction to effect advancement of the tow. In these embodiments, the piddler roll may double both as a piddler roll and a puller roll by reversing the direction of rotation of the piddler roll.

It is sometimes desirable that all rolls have a highly polished surface so as to provide the necessary traction for controlled advancement of the tow. Under some circumstances, however, it may be preferable to provide the piddler roll with a matte surface or to employ a fluted roll as is illustrated in cross-section as FIGURE 3, which will provide for more rapid release of the tow. The fluted roll has been found especially advantageously for handling of wet tow, since the surfaces presented to the tow may be highly polished for good traction while the interruptions in presented surfaces prevent adhesion of the tow to the roll as a result of surface tension.

It will be apparent that this invention is not limited to deposition in a rectangular receiver as described in the single embodiment illustrated, but is adaptable to a variety of shapes which may be desirable for some special purpose. It is entirely Within the purvue of the art to program both the lateral and the longitudinal oscillations to result in a uniform lay-down in a receiver having an odd shape such as oval or round, for example.

The advantages of this invention are seen in the nearly complete absence of damaging mechanical contact between the tow and surfaces and in the freedom from maintenance problems which are associated with piddlers known in the art. Since, as has been pointed out, many variations may be made in the apparatus of this invention without departing from the spirit and scope thereof, it is not to be limited except as set forth in the claims which follow.

What is claimed is:

1. An apparatus to deposit a running length of synthetic filamentary tow into a receiver comprising:

a roll capable of being rotatably driven reciprocally oscillatable in a direction substantially longitudinal to the path of advance of said tow to receive said tow from a cantable guide means and to gravitationally deposit said tow in said receiver, drive means for riving said roll,

cantable guide means cantable through a predetermined angle to dispose said tow in a continuous lateral oscillation over a fixed length of surface of said roll.

2. The apparatus of claim 1 wherein said drive means comprises:

a continuous flexible drive member adapted to move in a predetermined path and mounted on a support frame, drive means for the said belt,

a pulley rotatably mounted on a reciprocatable frame capable of reciprocal motion independent of said support frame, reciprocating means for said reciprocatable frame,

the said pulley being in contact with and adapted to be driven by the said continuous flexible drive memher and being free to reciprocate along a section of the path of travel of the said continuous flexible drive member, said reciprocating motion varying the speed of the said pulley by an amount equal to the diiference in velocity of reciprocation and the velocity of the said continuous flexible drive member,

the said pulley connected to and adapted to rotate the said roll, the said roll being further adapted to receive and direct the travel of said tow,

the said continuous flexible drive member being adapted to provide to the said roll a substantially constant speed equal to the speed of the said tow when the reciprocatable frame is at rest,

the said apparatus being adapted to receive the said tow with the said roll reciprocating substantially along the longitudinal path of travel of the said tow and adapted to receive the said tow from that direction which provides maximum speed to the said roller.

3. An apparatus to gravitationally deposit a running length of synthetic filamentary tow into a receiver comprising:

a roll capable of being rotatably driven reciprocally oscillatable in a direction substantially longitudinal to the path of advance of said tow and cantable through a predetermined angle to direct said tow in a continuous oscillation lateral to the path of advance of said tow, drive means for said roll.

4. The apparatus of claim 3 wherein said driven roll comprises:

a puller roll capable of being rotatably driven to receive said tow,

a piddler roll capable of being rotatably driven positioned substantially parallel to and in a rigid relation to said puller roll, said piddler roll additionally positioned to provide a wrap angle of at least 30 on said puller roll,

said rolls reciprocally oscillatable in a direction substantially longitudinal to the path of advance of said tow and cantable through a predetermined angle to direct said tow in a continuous oscillation lateral to the path of advance of said tow, drive means for said rolls.

References Cited UNITED STATES PATENTS 2,723,440 11/1955 Corbiere et al. 19-159 X 2,986,678 6/1961 Jackson et al. 19160 3,083,437 4/1963 Davis 2821 3,123,889 3/1964 Watts et al. 28-21 LOUIS K. RIMRODT, Primary Examiner. 

1. AN APPARATUS TO DEPOSIT A RUNNING LENGTH OF SYNTHETIC FILAMENTARY TOW INTO A RECEIVER COMPRISING: A ROLL CAPABLE OF BEING ROTATABLY DRIVEN RECIPROCALLY OSCILLATABLE IN A DIRECTION SUBSTANTIALLY LONGITUDINAL TO THE PATH OF ADVANCE OF SAID TOW TO RECEIVE SAID TOW FROM A CANTABLE GUIDE MEANS AND TO GRAVITATIONALLY DEPOSIT SAID TOW IN SAID RECEIVER, DRIVE MEANS FOR DRIVING SAID ROLL, CANTABLE GUIDE MEANS CANTABLE THROUGH A PREDETERMINED ANGLE TO DISPOSE SAID TOW IN A CONTINUOUS LATERAL OSCILLATION OVER A FIXED LENGTH OF SURFACE OF SAID ROLL. 